MudAllOverIt Posted June 5, 2008 Share Posted June 5, 2008 I'm about to fit a McNally Turbo Boost/EGT gauge to our 300Tdi and need to drill and tap a 1/8 NPT hole in the inlet manifold for the pressure sensor. I believe to do this properly I need (1) an R size drill, (2) a 1/8 NPT Taper Reamer and (3) a 1/8 NPT Tap. Anyone know of a good source for these items (in the UK)? Quote Link to comment Share on other sites More sharing options...
unclebill1 Posted June 5, 2008 Share Posted June 5, 2008 I'm about to fit a McNally Turbo Boost/EGT gauge to our 300Tdi and need to drill and tap a 1/8 NPT hole in the inlet manifold for the pressure sensor.I believe to do this properly I need (1) an R size drill, (2) a 1/8 NPT Taper Reamer and (3) a 1/8 NPT Tap. Anyone know of a good source for these items (in the UK)? Cromwells should do them. Quote Link to comment Share on other sites More sharing options...
mmgemini Posted June 5, 2008 Share Posted June 5, 2008 Cromwells should do them. I'll second that. mike Quote Link to comment Share on other sites More sharing options...
Tonk Posted June 5, 2008 Share Posted June 5, 2008 i wouldn't bother reaming. Quote Link to comment Share on other sites More sharing options...
callum Posted June 5, 2008 Share Posted June 5, 2008 i wouldn't bother reaming. having just fitted one, an 8.5mm drill bit does it and you need a 1/8NPT-27 tap. i got mine from a local place, 'engineering agencies' in Dunfermline. they had to order it in though and it cost about £17. i daresay i won't have to buy another in my lifetime though. some larger tap sets have it, they had a silverline box of taps in the same place for £30, so if you don't have many taps, that might be your best bet. i didn't need to do any reaming. Quote Link to comment Share on other sites More sharing options...
MudAllOverIt Posted June 5, 2008 Author Share Posted June 5, 2008 Thanks for info. Quote Link to comment Share on other sites More sharing options...
freeagent Posted June 5, 2008 Share Posted June 5, 2008 don't skimp on cheap taps though.. some of the chinese ones apear to be made of chocolate.. stick with a known make like Dormer.... The cheap ones are a right pain if they break... Quote Link to comment Share on other sites More sharing options...
Warthog Posted June 7, 2008 Share Posted June 7, 2008 Have used this vendor on Ebay a few times. Generally Dormer or Presto branded taps. http://cgi.ebay.co.uk/HSS-NPT-Tap-1-8-x-27...Q2em118Q2el1247 Quote Link to comment Share on other sites More sharing options...
western Posted June 7, 2008 Share Posted June 7, 2008 just threaded a modded temp sender with 1/8npt had to use a 8.4mm drill bit first then wound the taper/2nd/plug taps through, worked fine. Quote Link to comment Share on other sites More sharing options...
muzaz Posted June 7, 2008 Share Posted June 7, 2008 Just want to share an opinion that could save money and time sometimes I find that it works out easier and cheaper to do the work that needs to be done at a machineshop instead of buying the tools myself and doing it myself, as an example, some time ago I wanted to hone the cylinder bores, was tempted to buy a honing tool and do it myself, but with the price of the tool I got the block done in a machineshop, and done the right way, with the right tools. Another example was when I replaced the track rod with a stronger one, I could either buy a lefthand and righthand taps and a bar of steel to do it myself or else get it done at the shop... I chose to let the shop do it, ......30mm dia EN19 trackrod incl locknuts (without ball joints) cost me 30eur, the two taps would have cost double that. Quote Link to comment Share on other sites More sharing options...
tonycougar Posted May 6, 2009 Share Posted May 6, 2009 Hi, I have just bought an EGT gauge for my 200tdi 90, and to fit the sensor I need to drill+tap the manifold with 1/8 PT (thats what my instructions say). Is 1/8 PT the same as 1/8 NPT? Also would I need to seal it somehow, and with what? Where abouts on the manifold would be the best place to drill the hole? Quote Link to comment Share on other sites More sharing options...
Phil Hancock Posted May 7, 2009 Share Posted May 7, 2009 Seal it the same way as any other taper pipe thread, PTFE tape or a loctite pipe thread sealing compound. I would think that 1/8"PT is a typo and its NPT. Quote Link to comment Share on other sites More sharing options...
tonycougar Posted May 7, 2009 Share Posted May 7, 2009 Seal it the same way as any other taper pipe thread, PTFE tape or a loctite pipe thread sealing compound.I would think that 1/8"PT is a typo and its NPT. But won't the PTFE just melt, with it being on the manifold? Quote Link to comment Share on other sites More sharing options...
Ruuman Posted May 7, 2009 Share Posted May 7, 2009 But won't the PTFE just melt, with it being on the manifold? I would have thought so, I just used holts firegum to seal mine, it's sold everywhere and only a few quid Quote Link to comment Share on other sites More sharing options...
tonycougar Posted May 7, 2009 Share Posted May 7, 2009 I would have thought so, I just used holts firegum to seal mine, it's sold everywhere and only a few quid Doh!!!! Never thought of that Quote Link to comment Share on other sites More sharing options...
white90 Posted May 8, 2009 Share Posted May 8, 2009 Hi, I have just bought an EGT gauge for my 200tdi 90, and to fit the sensor I need to drill+tap the manifold with 1/8 PT (thats what my instructions say). Is 1/8 PT the same as 1/8 NPT? Also would I need to seal it somehow, and with what? Where abouts on the manifold would be the best place to drill the hole? No sealing compound required put the fitting in and tighten it up. For instance the 300TDI manifold is 3 piece and nothing is used to seal the bits together exhaust soot /heat does the job just fine. As for placing the Tech archive has pictures. Quote Link to comment Share on other sites More sharing options...
Phil Hancock Posted May 8, 2009 Share Posted May 8, 2009 Doh, i missed the EGT bit!!! Quote Link to comment Share on other sites More sharing options...
tonycougar Posted May 10, 2009 Share Posted May 10, 2009 I am begining to think this is a bigger job than I can handle. First I need to get the manifold off and I can't see that being a straight forward job. Its never been off while I've had it. Then I need to drill and tap a tapered hole (something I have no experience of). I am thinking I might ask/pay someone (who knows what they are doing) to do it. Quote Link to comment Share on other sites More sharing options...
stewy1984 Posted May 10, 2009 Share Posted May 10, 2009 ive just tapped my first (8) holes yesterday tony, never done it before. m10 in 10mm steel. used normal ratchet with 8mm socket, no need to buy tap wrench, got tap (second) from cromwells, cost afew quid and took 30 seconds a hole. really easy. Quote Link to comment Share on other sites More sharing options...
tonycougar Posted May 10, 2009 Share Posted May 10, 2009 ive just tapped my first (8) holes yesterday tony, never done it before. m10 in 10mm steel. used normal ratchet with 8mm socket, no need to buy tap wrench, got tap (second) from cromwells, cost afew quid and took 30 seconds a hole. really easy. I think I wouldn't be too scared to do a simple drill and tap, its just this is a tapered tap. Quote Link to comment Share on other sites More sharing options...
steve_d Posted May 11, 2009 Share Posted May 11, 2009 I think I wouldn't be too scared to do a simple drill and tap, its just this is a tapered tap. This is about the easiest tapped hole because you are tapping into an uneven and/or curved surface doesn't matter a F if it is square or not. Why do you need to remove the manifold? If there is space to get you drill down in there Or a flexi drive Or a rightangle drill adaptor then just drill it in situe. When you tap the hole get it started and wound in a few threads then remove it and try the fitting. It won't go in far enough and will give you a guide as to how many more turns you need on the tap. Keep doing this until you are happy with the depth. When you fit the sensor it will likely turn about two more times from finger tight. There is also nothing stopping you tapping a hole or two in some scrap metal on the bench. Use some oil on the tap. Take it easy and don't force it. The normal hand technique is to turn a bit then back of just over 1/4 turn to break the swarf chips. It's a feel thing. Steel will need this but cast iron less so. Enjoy Steve Quote Link to comment Share on other sites More sharing options...
tonycougar Posted May 11, 2009 Share Posted May 11, 2009 This is about the easiest tapped hole because you are tapping into an uneven and/or curved surface doesn't matter a F if it is square or not.Why do you need to remove the manifold? If there is space to get you drill down in there Or a flexi drive Or a rightangle drill adaptor then just drill it in situe. When you tap the hole get it started and wound in a few threads then remove it and try the fitting. It won't go in far enough and will give you a guide as to how many more turns you need on the tap. Keep doing this until you are happy with the depth. When you fit the sensor it will likely turn about two more times from finger tight. There is also nothing stopping you tapping a hole or two in some scrap metal on the bench. Use some oil on the tap. Take it easy and don't force it. The normal hand technique is to turn a bit then back of just over 1/4 turn to break the swarf chips. It's a feel thing. Steel will need this but cast iron less so. Enjoy Steve I was told I needed to remove the manifold to make sure none of the swarf (from the hole) ends up in there and consequently it would end up going through the turbo. Now I know that would not be good. Quote Link to comment Share on other sites More sharing options...
steve_d Posted May 11, 2009 Share Posted May 11, 2009 I was told I needed to remove the manifold to make sure none of the swarf (from the hole) ends up in there and consequently it would end up going through the turbo. Now I know that would not be good. OK did not think about the turbo. If I were doing it on my engine then I would drill the hole whilst holding a shop vac beside the drill then tap the hole with the tap coated in grease. Clean and recoat each time you stop to check if you have tapped far enough. Personally I don't think a small amount of swarf will worry the turbo but I wait to be flamed on the matter. Steve Quote Link to comment Share on other sites More sharing options...
tonycougar Posted May 19, 2009 Share Posted May 19, 2009 I am thinking about fitting it after the turbo. I realise the temp will be lower, but surely it should be a direct relation to the temp in the manifold. If I can allow for that then perhaps it will be OK there. The reason I am thinking of doing it this way is cos the manifold has never been off so I am not likely to be able to get it off and back on again. Plus to pay some-one to do it is gonna cost me. Does anybody know what the temp difference would be?? Quote Link to comment Share on other sites More sharing options...
Gremlin Posted May 21, 2009 Share Posted May 21, 2009 I am thinking about fitting it after the turbo. I realise the temp will be lower, but surely it should be a direct relation to the temp in the manifold. If I can allow for that then perhaps it will be OK there. The reason I am thinking of doing it this way is cos the manifold has never been off so I am not likely to be able to get it off and back on again. Plus to pay some-one to do it is gonna cost me.Does anybody know what the temp difference would be?? Just did mine, shop vac + grease on the bit, very easy and simple. G Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.